1. Field of the Invention
This invention relates to an automatic liquid control system for a clothes washing machine and more specifically for an automatic liquid level control system, liquid additive dispensing control system and a liquid temperature control system for a washing machine.
2. Description of the Prior Art
Various methods have been proposed in the past for controlling the amount of liquid added to a clothes washing machine to provide an optimum amount of wash liquid, and there have also been various methods proposed to control the temperature of the liquid added to arrive at a final desired temperature of the wash liquid.
U.S. Pat. No. 3,086,836 discloses an automatic liquid level control wherein a given volume of liquid is added to the clothes load, the volume not absorbed by the clothes load is measured, and that measurement is utilized to determine the additional volume of liquid to be added to obtain the proper total amount of liquid. U.S. Pat. No. 3,478,373 provides an automatic liquid level control which responds to the flow of liquid in a predetermined flow path to sense when the proper amount of washing fluid is present in the tub of the washer. U.S. Pat. No. 3,478,374 provides for an automatic liquid level control in an automatic washing machine which involves employing a sensing zone in proximity to the axis of the agitator, applying a reduced pressure at the sensing zone, and then introducing additional amounts of liquid into the machine when the liquid has been depleted from the sensing zone as a result of an excessive amount of wash fabric being present in comparison to the amount of washing liquid. U.S. Pat. No. 3,498,090 utilizes a control system for use in automatic washers to automatically control the quantity of liquid added to the machine's tub during the wash and rinse operations by using a torque signal generated in the machine by action of the agitator.
U.S. Pat. No. 4,330,081 provides a water temperature control system for a clothes washing machine in which the temperature of the incoming mixed hot and cold water is periodically sensed, and the accumulative average temperature of the mixed water is compared to a desired temperature value stored in the memory of a microprocessor. When the comparison results in a temperature difference which exceeds a predetermined error limit, the appropriate hot and/or cold water valves are turned off or on causing the average temperature of the mixed water to change toward the desired temperature value.